Diode laser annealing of epitaxy Ge on sapphire (0 0 0 1) grown by magnetron sputtering

In this work, magnetron sputtering was used to epitaxially grow Ge films on sapphire at low temperatures (400 °C–500 °C) and diode laser annealing was employed to improve the crystallinity of the Ge films. The deposition temperature might slightly influence the crystallinity of the Ge film through affecting the diffusion rate of Ge. After laser scans of milliseconds exposure time, significant defect density reduction and removal of polycrystalline portion are achieved. Magnetron sputtering combined with diode laser annealing offers a low-cost and fast method in fabricating high quality single crystalline Ge on sapphire which is potentially capable of large-scale production.